Quick-cooking cereal and method of making same



Patented Sept. 22, 1953 UNITED STATES ATENT OFFICE QUICK-COOKING CEREAL AND METHOD OF MAKING SAME No Drawing. Application July 2, 1953, Serial No. 366,046. In Canada March 5, 1951 6 Claims.

This invention relates to a pro-cooked cereal and a method of preparing the same and particularly to a pro-cooked oatprod'uct.

This application is a continuation-in-part of our co-pending application Serial No. 259,313, filed November 30, 1951, now abandoned, which in turn was a continuation-in-part of our application Serial No. 161,744, filed May 12, 1950, now abandoned.

The pre-cooking of cereal is not a new art, but the problem of pro-cooking cereals, drying them, and then having them reconstitute rapidly in water, without loss of flavor, palatability, or granular identity has heretofore not been satisfactorily solved.

The formation of the present product involves the following factors:

1. In order to procure a uniform product, the

moisture content of the material should be uniform as between kernels and uniform throughout each kernel. Depending upon the type of cereal employed, the moisture range will vary and the uniformity may be obtained as desired. In some instances, it is preferred to temper the kernel, particularly rice. 7

2. The product should be cooked by steam or otherwise under conditions which establish a proper moisture content and cause the starch to become uniformly gelatinized so as to bring the product to a sufficient state of plasticity properly a to expand. The conditions should be adjusted so that each kernel should be cooked to substantially the same degree and in addition these conditions are preferably of such a nature that the non-condensable gases in the kernels are removed therefrom. This latter condition may be established under vacuum conditions under which the contained moisture boils and washes out the non-condensable gases in the kernels. During the cooking a bleed or purge line is maintained so that any non-condensable gases generated during the cooking or supplied with the cooking may be eliminated.

3. When the product is properly cooked and is at the proper moisture content, it is suddenly shot into a vacuum zone, causing expansion of the product. The conditions of the resulting explosion should be such'as to cause cold setting of the product. The temperature is determined by the vacuum conditions into which the product is fired and the ability to maintain these conditions during the resulting explosion and concomitant expansion of the product. This means that with commercially practicable vacuum quipm t, he xpan on chamber of necessity has a volume enormously greater than the cooking chamber. In actual practice, this has been of the order of 330 to 1 in volume using vacuum equipment having the capacity of pulling a vacuum of 0.2 inch of mercury absolute from atmospheric conditions in a period of about 15 minutes. The preferred vacuum at the start of the expansion of the product is of the order of 0.1 to 0.2 inch of mercury absolute. In such apparatus the pressure may ride up somewhat during the explosion step. It is preferred to continue evacuation of the expansion chamber during the explosion and to maintain it at as low a pressure as is practicable. The temperature to which the product is cooled is normally determined by the vacuum condition during the explosion step. For example, tests have shown that when 20 lbs. of rice are exploded from a one cubic foot cooking chamber into a 330 cubic foot expansion chamber using the vacuum equipment described above, the pressure in the expansion chamber being maintained at approximately 0.1 inch of mercury absolute, the product attains a temperature of approximately 27 F. It is believed that the results follow because of a blast or velocity effect caused by the uniform and sudden passage of the steam outwardly, the degree and speed of which is determined by the first blast of the explosion providing that explosion is free to continue until all of the product has been subjected to it. Because of this fact, the pressure condition in the product apparently stimulates that of the initial vacuum in the chamber, just as an exhaust pipe of a motor will draw in air through a vent even when the pressure within the exhaust pipe is above atmospheric provided gases are moving through the pipe toward the exit.

4. The starch is substantially completely gelatinized.

5. The time-temperature relationships are sufficientl short and low respectively, that browning or scorching is avoided.

6. The product must not be so much cooked as to change the cell walls so as to render them impervious to steam, since otherwise they would rupture on expansion.

'7. The moisture content, and cooking time, temperature and pressure, and the vacuum into which the product is fired are selected to produce a product which is vacuum expanded, but avoids undue enlargement of the particles such as occurs in the manufacture of ordinary puffed cereals, and has a hydration rate of at least /3 greater than that of the original cereal grains after immersion in water at a temperature of about 260 F. for a period of about 20 minutes.

Removal of the non-condensible gases from the cereal, cooking, and vacuum expansion are preferably carried out in a puffer of the type disclosed in the Doyle Patent No. 2,627,221, issued February 3, I953; In suclr an apparatus a steaming chamber provided within which the product may be placed. This steaming chamber is connected by a triggered door to an expansion chamber. The expansion chamher is preferably kept at a w pressure, means being provided to maintain a low pressure during the expansion. The steaming chamber is provided with an evacuating means; steam means, and usually with a purge or bleed line through which non-condensiblei gases can be eliminated as well as some condensed steam which develops during steaming.

The steps of removing the non-condensible gases from the product in cooking may be carried out before introduction. into: the puffer, but convenience is best served by carrying" out the operation in one device.

In the case of oatsparticularly steel-cut cats, the bran continues to adhere to the starch por tions of the grain, even though the latter; have substantially enlarged. Whether the bran itself is stretched or enlarged is not. clear. The origi nal small wrinkles which. are characteristic of the bran in oats are not usually present in the treated material and the surface of. the bran has a somewhat more: vitreous appearance and appears to have actually. stretched as well as smoothed out the wrinkles. In. some instances, the bran has cracked due to the expansion strains.

On fracture, or if already out before treat.- ment, the vacuum expanded. quick-cooking oat product appears to consist of ailarge' number" of bubbles ofabout the same shape and consids erably larger than the cells originally present. Possibly, some of these cellular formations have been produced by coalition of cells in the original starch material, but the appearance is still cellular. The color of the vacuum expanded oat material is white like a snowball.

In some instances, the exposed starch surfaces of an oat out before vacuum expansion have a somewhat more vitreous appearance than the immediately underlying portions, but this is not always the case. All of the starch material which has been vacuum expanded has a gelatinized, vitreous appearance, somewhat like ice; but the surface characteristic just referred to is one in which the product has the appearance of some interfusion between the cells of the surface to provide a greater continuity to the vitreous appearance.

Upon rolling, flaking or crushing, the appearance of the material, although whiter than the original unexpanded material, loses some of its vitreous appearance to the naked eye, but continues to retain much of it when viewed under the glass as, for example, at to 40 powers.

The cat product may be prepared in steel-cut form or the steel-cut material may be rolled or flaked. In either event, the material is capable of quick-cooking and rapid re-hydration. Although fiavor and texture are affected by rolling or flaking, it is the quick-cooking and the rate of re-hy'dration which are particularly improved by rolling.

The cat product of this process has a volume from 1% to 3% times the original oat grains. Put conversely, the specific gravity as determined from cup weights is from 28.5% to 60% of the specific gravity of the original grains.

The following Table I gives a list of treatments accorded to regular, Clinton brand, steel-cut groats, each groat being severed in two or three pieces in the cutting process. The: first column gives the exam le number; the second column gives the loading in the cooking or steam champer, the size of this chamber being approximately 13.. inches in. diameter, 16% inches in depth aneinavihga voiurne of 2,175 cubic inches. Column 3' gives the amount of pro-tempering applied. to the grain. The next column gives the tempering time. Ehus, in the first example, 2

pounds car-water was applied for two hours to 10 pounds of oat. greats. before the application of the. cooking-expanding cycle.

Column '5 gives the treatment provided before the expansion. Thus, in Example 1, the oats were placed in the steam chamber, the pressure raised. to- 35' pounds per square inch gauge and held there for 5: minutes. In all cases, before application of the-steam, the oats had been subjected to a vacuum of the order of 0.2 inch of mercury absolute, the cats being at a temperature not less than about 40 F. so as to remove air and other non-condensiblev gases from the oats, and: then the steam was admitted at a predetermined rate to reach the gauge pressure. In all cases, unless specified otherwise, a bleed line was kept open during the introduction of the steam into the steam chamber so as to remove condensate and any non-condensible gases which might be formed in or introduced into the chamher.

In all cases, after the completion of steaming, the triggered door of the puffing apparatus was opened instantaneously and the oats fired into the expansion chamber, which was at a pressure of about 0.2 inch of mercury absolute. The pressure within the expansion chamber was maintained at, a low point by continuing the evacuation during the expansion, and normally the pressure in that chamber was not permitted to exceed 1% to 2 inches of mercury absolute. In some instances, however, We have operated successfully with the pressure in the expansion chamber following explosion riding up as high as 3 to: 7 inches of, mercury absolute as measured on a standard mercury manometer, but in most instances, the pressure was reduced below 1 inch of mercury absolute within a few minutes, and before Ire-imposition of atmospheric pressure.

The oats, prior to tempering, contained about 8 to 10% moisture. Above about 3 pounds of water for 10 pounds of cats. in the tempering operation tends to produce clustering of the grains on pufiing. Tempering is not required with oats and the flavor of the cats if not tempered is preferred by many to the flavor produced upon tempering.

Table I (continued) v Table I (continued) L Tem er Treatment Before Load Temper Treatment Before Example S??? Temper Tin i e Expansion 5 Example Size Temper Time Expansion ..do 3 hours... Steam pressure 559% for 50 10# do do Steam pressure to 100# 10 min. in 30 sec. 10# 3t water 2hours Steam pressure 45# for 51 101? do do Steam pressure 5# for D min.raise to 102? 4. ate 3hours o. 10# gate n 5hours Do 10 52 10# washed .do Oats gamed 2.88#water 10# 2# water 5 hours i Steam pressure 55# for during wash. Steam 5min. pressure 5# for 45 10# 3#water 6hours Do. mm.ra1seto100#. 10# 2#water 2hours Stea pressure 55# f 53 10# none do Steam pressure 5# for St sec. 55#f 1O0#1Ilin.-lal50 to 1 .d 2 hours. eam pressure or O# o 2 2min. 54 10# do ...doi SteampressurelOitabs. 10)? .do 5 hours Steam pressure 55# for for 35 to 3 min. l00#. 10# d 2% hours Steam pressure 65;; for 55 45# do .do Steam pressure to 100# l min. in 65 sec. 10# d 2 hours Steam pressure 55# for 56 45# washed -do Oats gained 4%# water S min. t 1 (luring tzasg-aisteam 1 none team pressure 0 00 pressure 0 .in 55 0# mm in 25 see-hold 1s sec.

sec. 57 20;? none .do .i Steam pressure to 75# 13 10,; do do Steam pressure to 100# in 33 b Stin20 sec.hol %5 58 10# 2# Water"... 2hours Stea12n pressure to 75# 1 3 t 5 0111s..-. eam pressure 0 m- {sea 19 0# wa er in sec. 59 10# do 3hours Antloiudant added to 20 10;; none none Steam pressure to 100# temperwater. Steam for 10 min. 25 pressure to 75# in 28 21 10# .do do Steam p essure to 10U# Sm in 15 see.ho1d 45 60 10# washed 18%hours. Steam pressure to 75!; sec. in24sec. 22 10# 3%#water. 41101115.... Steam pressure to 100# 61 10# do 19%hours. Glycerine added. in see-hold 30 Steam pressure to Se 75# in 26 sec. 23 38# none none Steam Pressure to 100# 62 10# do 19%hours- Glycerine-i-NaHCOz 70 Sea 30 added. Steam pres- 24 45# do ..do Steam pressure to 100# sureto 75#1n23 sec.

a in 00 63 30# none none Steam pressure to 100# 25 45# d do Steam pressure to 100i? i1147S8C.

m 18 S 64 10# do do Steam pressure to 26 do do Steam pressure to 100# a i 1 0 65 10# do do Steam pressure to 75# 7 45# d .do Steam-pressure to 100# r i 21 1n 95sec. 30 66 l0# do do Steam pressure to 100# g 40# d do Steam pressure to 100# i 26 ill 65 67 10# do do Steam pressure to 100# 29 40a! lo do Steam pressure to 75# {01.4mm

v in 55SeC-1101f15S68- 68...... lO# do... do.... Steam pressure to 100# 30 4 do Steam pressure to 65# 1 i rzmin,

in 65 sec.ho1d 10 69..."--- 10# do do.. Steam pressure 55, 1 for sec. 40 15 min.-raise to 31 40# r .-.do do Steam pressure to 55# 1 O0#ho]d 1 mm.

Stm sec. t 45# v o 32 40# do 32 5 ff l i old 30 All of the examples listed above were a satisfactory quick-cooking oat product having the d Steam ressure to 25# 40# 0 in30 See. above described properties. The optimum cycles fggg gg 45 were those in the range of -75 pounds steam 40# do --.do Swain) pressure to 65# p su in sec. 1 Steam pressure mum The oat product may be cooked by using in26 sec, cups of water with teaspoon of salt, the water 1% 2 3 fgf to boiled, and then 1 cup of the oats in rolled form d do Stear2n pressure to e5# 59 stirred in, boiled for one minute while uncovered,

' Osec. 4% do Steam pressure to 100; removed from the fire, covered, and allowed to in 64 sec. stand for two minutes. The product may be pi e- 101? 68; pared by pouring hot water onto the rolled oats, 10# d -d0 Stzeam pressure 5 a or by bringing rolled oats plus cold water to a 5min.--raise o 10 do steam pressure 5# for 55 bed, but these latter two methods give a greater y a min.raise tg#1(}0# raw oats flavor than the method first described. g" 1 hours cam pressure or a Water 4 45 to 100# In the case or prepar ng a p1 ecooked r ce prod 10# do 3 hours..- stggmpress re 5# 6 uct the following additional factors are lnvolvcd:

r Inm.-ra1se to r H 10 do zhoursun steam presspre 5# for a In order to procure a um form product, tne

' 5 min.ra1se to 100# moisture content of the material should be unifgfli g g gg gg iorm as between kernels and. uniform throughtimes, and evacuate out each kernel. The preferred range is 18% Egg? to 26% with approximately 23% a to 22279 proigggjhga steam to v1d1ng the maximum benefits. The unnornuty in sec. r 47 m 2# WISH Alternate/1y, spam at may be obta ned as desired, but the tempering for 5 m em t method heremafter described is preferred.

gg gg ggg fg ggi g b. The moisture content, and cooking time, th%1x] acuaion1st5 temperature and pressure and the vacuum into 133th 1 2 which the product is fired are selected to pro- 4s 1o# none none st im ressu et a 70 duce a product having a volume from 1% to 3 49 m ggt f gg g at times, the volume of the original kernels as de- %s# for 2 ng termmed by their cup Weights. Put conversely,

m t 3,0 a g g ig fgl the specific gravity as determined from cup 8th ggacuattion is 5 weights is from 28.5% to 60% of the specific en Seam gravity of the original kernels. The preferred in 24 sec.

relationships are sufiiciently short and low respectively that the rice product from a nutritional standpoint has a positive protein efficiency whereas. previous cooked rice products have a negative protein efficiency. Likewise, the thiamine content of the rice product is relatively very high compared to prior similar products.

The rice product of this process has a volume from 1% to 31 times the original kernels. The shape of the original kernels is roughly maintained, although the outer surface of the ex panded material is rough. The product is not case hardened so far as can be observed, but is uniform throughout. On cross section, the kernels have a large number of relatively small cavities substantially uniformly distributed throughout the interior. These cavities while by no means spherical, are generally rounded at their protuberances, indicating that they were formed by pressure outwards rather than by shrinkage and collapse inwards. The product is capable of ready hydration to form a product resembling ordinary cooked rice without loss of the identity of the kernels and when so hydrated resembles ordinary cooked rice, although its flavor is different from that of ordinary cooked rice or of prior quick-cooking rice products.

The product is not transparent but is translucent, having a milky-white appearance. Under the glass the individual cell walls appear transparent, although not completely clear.

ranverse fracture rings frequently occur at spaced intervals along the kernel, from '7 to of these rings being customary but apparently not necessarily formed during the puffing. In fact in many cases, these may be seen in the washed material before cooking.

The present product has been made from rice from various sources. Texas, Louisiana, Arkansas and California varieties have been employed. Some of the rice has been long grain, other, short grain. Arkansas Riceland brand and Texas Patna type are examples of the long grain variety. The Patna, however, has a. smaller average diameter and is much harder. Texas and Louisiana rices are normally fiinty, while Arkansas rices are softer. California rice is normally short and fat grained material. Normally, the Texas Patna rice is milled to 99% purity and conformity, while the other rices are milled to 95% and 96%. The Patna and Riceland products are normally whiter than the others. Quick-cooking products may be made from all these types, but the cooking and pufling procedures may have to be varied in the individual cases depending upon the type of rice and its condition.

To obtain a quick-cooking rice product having uniformly puffed grains and which is a better marketable product, it is preferred to process rice having a moisture content of about 18% to 26% uniformly distributed throughout the individual cells of the rice kernels.

To so condition the rice, it may be placed in water and allowed to stand with occasional agitation. It may also be placed on a screen, spray washed, and then water added :to the rice which is allowed to stand for a time with occasional agitation. A third method which appears to be the .most satisfactory, is to place the rice on a screen and spray wash with warm water for a period of 1 A; to 3 /2 minutes depending upon the condition of the rice; then, after draining the excess water from the outer surface of the rice kernels, temper by placing the kernels in a closed container and allow them to stand for a period of time with occasional agitation until a moisture content of from 18% to 26% is uniformly distributed throughout the individual cells of the rice kernels. Generally speaking, this will take from 1 to 1% hours and the temperature of the rice will rise from about "70 F. to F. as a result of the warm water wash. The rice may be left in the container for 24 hours or longer at room temperature and upon removal from the container has a dry outer surface.

It is preferred to use water at a temperature of from 95 F. to F. when spray washing and the length of time of this washing will vary according to the temperature of the water being employed and the condition of the rice.

The tempered rice at a temperature of not less than 91 F. is placed in the steam chamber; the pressure in this chamber is reduced to about 1%; inches of mercury absolute or less and held long enough to remove substantially all of the air and other non-condensible gases from the rice kernels, i. e., about two minutes; and then steam is introduced. The atmosphere of steam is maintained until the rice is substantially com pletely cooked without loss of cellular identity. After cooking has been completed, the rice is fired from a steam pressure substantially above atmospheric in the steam chamber into the expansion chamber which is maintained at about 2 inches of mercury absolute and preferably 0.1 to 0.2 inch so as to expand and cold set the rice kernels. During the expansion step, the momentary pressure may ride up as high as 3 to '7 inches of mercury absolute as measured on a mercury manometer. This firing is done by suddenly releasing the triggered door of the expansion chamber and the resulting explosion ejects the rice into the expansion chamber. The rice product is then dried in any number of ways, as by exposing the rice to air or by circulating warm dry air about the expanded rice product.

The cooking-expanding cycles may be varied. The rice may be subjected to a particular steam pressure for a given period of time and then the steam pressure increased to from 35 pounds to 65 pounds gauge and held for a period of time (usually shorter) following which the rice is fired into the exacuated expansion chamber. Better control of the variables and best results in the rice product are abtained by slowly increasing the steam pressure from about 1 inches of mercury absolute to a final pressure of about 35 pounds to 65 pounds gauge at a uniform rate, sometimes followed by a holding period at the final steam pressure so that the rice is complete- 1y cooked without loss of cellular identity. The cooked rice is then fired into the expansion chamber which preferably has a pressure of from 0.2 to 0.1 inch of mercury absolute.

The actual values of the variables in the cooking-expanding cycles of this method depend upon the condition and type of rice being used, as well. as the degree of expansion desired.

It is preferred not to shoot into the expansion chamber from about 65 pounds gauge or from be- 9 low 35 pounds gauge. At pressures above 65 pounds gauge the rice product clusters and tends to stick to the chamber walls. Below 35 pounds gauge, the rice product lacks uniformity in size and has a slight hardness of texture.

The pressure within the expansion chamber is maintained at a low point by continuing the evacuation during and after the expansion of the rice. Normally, the pressure in this chamber was not permitted to exceed 1% to 2 inches of mercury absolute. In some instances, we have operated successfully with the pressure in the expansion chamber following explosion riding up as high as 3 /2 to 7 inches of mercury absolute as measured on a standard mercury manometer, but in most instances the pressure was reduced below 1' inch of mercury absolute within a few minutes and before reimposition of atmospheric pressure.

The following examples show cooking times which prove satisfactory:

(1) Texas Patna rice was placed in the steam chamber, the pressure was raised by introducing steam to 10 lbs. gauge during a 10 minute period. The pressure was then raised quickly to 35 lbs. gauge and then fired.

(2) California Pearl rice was steamed quickly to 20 lbs., held there for 20 minutes, steamed quickly to 40 lbs., held there for one minute and fired.

(3) California Pearl rice was steamed quickly to 20 lbs., held there for '7 minutes, steamed' quickly to 50 lbs., held there for seconds and 10 Patna and California Pearl rice were each used in this cycle.

(14) Texas Patna rice was placed in the steam chamber, pressure raised by steaming to lbs. during 2 minutes and then fired.

(15) Arkansas Mandalay rice was placed in the steam chamber, pressure raised by steaming to 35 lbs. during 1 minute, held there for ten seconds and then fired.

(16) Arkansas Mandalay rice was placed in the steam chamber, pressure raised by steamin to 35 lbs. during 5 minutes, held there for 3 minutes and then fired.

(17) California Pearl rice was placed in the steam chamber, pressure raised by steaming to 35 lbs. during 5 minutes, held there for 30 seconds and then fired.

(18) Rice was placed in the steam chamber, pressure raised to 35 lbs. during 5 minutes, held there for 1 minute and fired. This cycle was used on Arkansas Mandalay rice and California Pearl rice.

(19) Rice was placed in the steam chamber, pressure raised to 35 lbs. during 5 minutes, held there for 1 /2 minutes and then fired. This cycle was used on Arkansas Mandalay rice and California Pearl rice.

(20) Arkansas Riceland rice was placed in the steam chamber, pressure raised to lbs. during 5 minutes, held there for 2 minutes and then (4) California Pearl rice was steamed quickly to 20 lbs., held there for '7 minutes, steamed quickly to 40 lbs., held there for 30 seconds and fired.

(5) California Pearl rice was steamed quickly to 20 lbs., held there for 20 minutes, and then fired.

(6) California Pearl rice was steamed quickly to 20 lbs., held there for 10 minutes, steamed quickly to 40 lbs., held there for 15 seconds and then fired.

('7) California Pearl rice was placed in the steam chamber, pressure raised by steaming to 25 lbs. during 5 minutes, held there for 1 minute, and then fired.

(8) Arkansas Mandalay rice was placed in the steam chamber, pressure raised by steaming to. 30 lbs. in one minute, held there for 10 seconds and then fired.

(9) Arkansas Mandalay rice was placed in the steam chamber, pressure raised by steaming to 30 lbs. in 5 minutes, and then fired.

(10) California Pearl rice was steamed quickly to 30 lbs., held there for '7 minutes, steamed quickly to 40 lbs., held there for 30 seconds and then fired.

(11) California Pearl rice was steamed quickly to 30 lbs., held there for- 10 minutes and then fired.

(12) Rice was placed in the steam chamber, pressure raised by steaming to 35 lbs. in 5 minutes, held there for 2 minutes and then fired. This cycle was followed using both Arkansas Riceland and Arkansas Fortuna rice.

(13) Rice was placed in the steam chamber, pressure raised by steaming to 35 lbs. during 5 minutes and then fired. Arkansas Fortuna,

Arkansas Riceland, Arkansas Mandalay, Texas steam chamber, pressure raised by steaming to 4.0 lbs. during 5 minutes, held there for 30 seconds and then fired.

(24) California Pearl rice was placed in the steam chamber, pressure raised by steaming to 40 lbs. during 5 minutes, held there for 1 minute and then fired.

(25) California Pearl rice was placed in the steam chamber, pressure raised by steaming to 40 lbs. during 5 minutes, held there for 1 /2 minutes and then fired.

(2 6) California Pearl rice was steamed quickly to 40 lbs., held there for 5 minutes and 15 seconds and then fired.

(27) California Pearl rice was steamed quickly to 40 lbs., held there for 10 minutes and 15 seconds and then fired.

(28) California Pearl rice was steamed quickly to 49 lbs., held there for 6 minutes and then fired.

(29) Rice was steamed quickly to 40 lbs., held there for 7 minutes and then fired. Arkansas Riceland and California Pearl rice were used.

(30) California Pearl rice was steamed quickly to 40 lbs., held there for 9 minutes and then fired.

(31) California Pearl rice was steamed quickly to 40 lbs., held there for 8 minutes and then fired.

(32) Texas Patna rice was placed in the steam chamber, pressure raised by steaming to 45 lbs. during 5 minutes, held there for 2 minutes and then fired.

(33) Rice was placed in the steam chamber, pressure raised by steaming to 45 lbs. during 5 minutes, and then fired. Arkansas Riceland,

11 Arkansas Famine, Arkansas Mandalayar'id Texas 4 r e ew ere ed-t at H .v I

, (34 caufer iejpe ri nee wee pieeea in the steam chamber, bresisure raised by steaming to it'i lbs. dur ing'5 minutes, held there for 1 minute and th'en fired. I

(3 5;) California Pearl rice was steamed quickly to '45 lbs, held 't l'i'e're for 7 minutes andthen fired. H (36) California Pearl rice was steamed quickly ljti) 45 lbs, held there for 11 minutes and then fired.

(27) Ride was mated in the steam chamber, gressure raised by steaming to 50 during 5 minutes, held therefor 1 minute and then fired. California Pearl and Texas Patna 'rice were used.

(38) California Pearl rice was placed in the steam chambenpressure raised by steamingto 50 5 minutes, held there for 2 minutes rid thei area, e I

(39) California Pearl rice was steamed quickly to '50 lbs, held there for 5 minutes and 15 seconds and then fired. I n

K40) California Pearl ri'eewas steamed quickly to 5015s,, held therefor 6 minutes and then fired.

rhefr'eeumne product, a's .already stated, has a sb'ecific gravity a'pbrokim'a't'el'y 28.5% to 60% that of the original material. For eiiarnple, Texas Patna rice before processing has a eight of 180 grains bier cup, and after nro'ces'sing, about 60 grains her cup.

. e e'lri e P ep red. in h m e iy scribed is bo ile'd for me minutes, 'as cempared to r "quick-tearing materials, the prior materials acq re afslight gluey appearance and texture, whereas the present product does not acquire such an objectionable apbearance or texture. whehjtee ee an Amylo graph, as eemper'e to a prio i' quick-booking rice, the bresent product thee used at 50 grains per 450 ml. showed cons r e ixr e te ietherieent mieel up 129 99 (3., with a complete reversal, however, a 95C- .Thie..e1 i ehe r ct was steady, but for the prior product had a change of trom between Q OfflC an d 96 0., indicating a lack of eeei e ee ie ea a. l ,0 levini he it u we ma e e e er i e the average rate of hydration of the quick-cooking r r lleie thi l e emi a- Fe a h n the hyd t on d te inati n ere made n, p a e usihgdBO gra n samples One sample of each run was placed in a double boiler containing one quart S4 eramex ma ta ned at abeut 2.09 F. t r. l ndow m n rva the water-rice mixture was poured into a strainer wh e mi ll 1 1.9? th reewet Pas into themeasuring cup in frorn l0 to seconds. After weighing the free water, it and the rice were ee n le e in. h euh eb il r- The d ere in weight b etween th e free water in the double b l 311st p i teiq ei eethed qe e mm ther and the weightofire'e water at each interval was the amountolf water absorbed by the rice for that p i reri de time e. abso be mo 'tfi'i ofl the second sample of each run was determined in the same manner except that the hydration determinations were made at 10, 20 and minute intervals H V It was fauna that water was absorbed by the present quick-cooking rice product at an average rate of 22% of the original dry wightper minute arfter l minutes, and for the next laminates. The deviations from this hydration rate were from +6 2%. Whencompared with the hydration rate of prior quick-cooking rice, the

of invention i'ehyiiiet'es in ori e hal i Thiamine as M11- ligrams per 100 grams Raw Texas Patna BiccM; 0. 0817 0. 0693 0.095 Precooked Texas Patna 'Rice Product of v this Invention 0. 0174 i 0. 0276 0 030 Prior Qulck-cooking Rice 0.0070 0.0095

It is readily seen that theguiclg eooking, rice product retains atleast one-third and up toftwothirds oi the original thiamine content of the original rice. thefother handfprior quick co'oking rice only retains from 5% to 14% or the original thiamine content The rice productpreviously described is normally cooked by mixing from to 1 cup of cold water with one 'cupof rice, adding salt to taste and then bringing quickly to a boil while uncovered. If the cup weight of the material is '60 to 70 ,4; cup of water is used per cup 'of rice; from '70 to '85 grams, 7 cup of water; and above grams, 1 cup of Water. The product is then fiufied lightly onceor twice with a fork, but not stirred, and isthen covered and removed from the heat and allowed to stand for ten minutes t eeervina Iii the case of producing a'quiek-e 'ekine wheat product, hard fwinterlwheat finely ground in aceereanee with new practice, was employed. S uch ,a material, prigr to pre-coolzing, is now available fon the marketunder the me, Blue Cross Whole Wheat. Its cooking time is normally about ten minutes.

The material, prior to treatment, had a -cub weight of a pr xim ateiy 117 grams.

The material we processed in ten pound lots, without any rhoistening "or tempering operation. Tempering may be employed, but it has not been found to improve'the material and, in some cases, has a deleterious effect.

The wheat is placed in the steaming chamber, nd f iyl e iq eeli ied ut to appro m te y, to 02 inch of mercury absolute for about two minutes the wheat being at a temperature of not less than about 40 F. to remove the noncondensiblegasee iromthewheat grains. Steam is then introduced t0 the team ng 'chamber accompanied by continued purgin to cool; the preduet i e a qn e t a n condensible gases The product is cookedsufficiently to gelatinize the starch, in activate enzymes and supply sufllcient plasticity I 'or vacuum expanding The. amou t ,o k n ,required will vary c 0nsid.er ab1y with the characteristics of the wheat grain, butmay readily be determined by a preliminary test for any parti'cular lot, a

The preferred cooking cycle is to introduce steam to reach 50 pounds per square inch gauge in 20 to 25 seconds, after which the material is expanded by opening the triggered door to the expansion chamber which is at a pressure of about 0.2 inch of mercury absolute. Normally the pressure in the expansion chamber is not permitted to rise above about two inches of mercury absolute until cold setting of the vacuum expanded wheat grains occurs. In some instances, however, we have operated successfully with the pressure in the expansion chamber following explosion riding up as high as 3 to 7 inches of mercury absolute as measured on a standard mercury manometer, but in most instances, the pressure was reduced below 2 inches of mercury absolute within a few minutes and before re-imposition of atmospheric pressure.

In one specific example, the steaming cycle was 50 pounds per square inch gauge of steam pressure reached in 23 seconds. In another, it was 75 pounds per square inch gauge of steam pressure reached in 26 seconds. In another, it was 35 pounds per square inch gauge of steam pressure reached in 22 seconds. In another, it was 25 pounds per square inch gauge steam pressure reached in 22 seconds.

After expanding, the product was dried by the introduction of superheated steam at about one inch of mercury absolute into the expansion chamber and continuing this operation for 10 minutes. That is, steam was continuously admitted while the evacuating apparatus was operated so that the pressure did not rise above 1 inch of mercury absolute. It is preferred to have a moisture content of approximately 10-15% in the product before further processing.

The expanded and dried whole wheat was then put through corrugated rolls. These corrugations cut the grains up to some extent, broke up clusters, and removed some loose starch from the grains.

The vacuum expanded wheat product has a volume from 1 /3 to 3 times the original wheat grains. Put conversely, the specific gravity as determined by cup weight is from 28.5% to 60% of the specific gravity of the original wheat grains. It is granular in appearance, the grains being of a mixed brown and white color and substantially the shape of the original grains. It is capable of remarkably fast water absorption and can be cooked in approximately thirty seconds, as compared to ten minutes required for the original material.

In cooking, one cup of the processed wheat is slowly stirred into one and one-quarter cups of boiling water containing a quarter teaspoon of salt. The boiling is carried out for thirty seconds, after which the wheat is ready for serving.

The cooking operation increases the moisture content of the grain approximately 1% for each twenty to twenty-five degrees F. increase in temperature. This increase is lost on vacuum expanding, and the loss of water, plus the sudden cooling is believed to cause setting of the plasticity of the walls so that they will not collapse upon subsequent increase in pressure.

The starchy portions of the processed wheat are translucent. The surfaces have a somewhat vitreous appearance. The bundle of starch cells somewhat resembles a snowball.

In the case of producing a quick-cooking farina product, regular farina, which is the centers of hard wheat, was employed. Such a material, prior to pre-cooking, is now availabl onhthe 14 market. Its normal cooking time is from two to five minutes.

The material, prior to treatment, had a cup weight of approximately 168 grams.

The material was processed in ten pound lots, without any moistening or tempering operation. Tempering may be employed, but it has not been found to improve the material and, in some cases, has a deleterious effect.

Farina is placed in the steaming chamber, and evacuation carried out to approximately 0.2 inch of mercury absolute for about two minutes, the farina being at a temperature of at least about 40 F. to remove the non-condensible ases from the farina particles. Steam is then introduced to the steaming chamber accompanied by continued purging to cook the product and remove any condensate and non-condensible gases. The product is cooked suficiently to gelatinize the starch, inactivate enzymes and supply suificient plasticity for vacuum expanding. The amount or" cooking required will vary considerably with the characteristics of the farina particles, but may readily be determined by a preliminary test for any particular lot.

The preferred cooking cycle is to introduce steam to reach 35 pounds per square inch gauge in 20 to 30 seconds, after which the material is expanded by opening the triggered door to the expansion chamber which'is at a pressure of about 0.2 inch of mercury absolute. Normally the pressure in the expansion chamber is not permitted to rise above about two inches of mercury absolute until cold setting of the vacuum expanded farina particles occurs. In some instances, however, w have operated successfully with the pressure in the expansion chamber riding up as high as 3 to 7 inches of mercury absolute as measured on a standard mercury manometer, but in most instances, the pressure was reduced below 2 inches of mercury absolute within a few minutes and before re-imposition of atmospheric pressure.

In one specific example, the steaming cycle was 35 pounds per square inch gauge of steam reached in 30 seconds. In another, it was 40 pounds per square inch gauge of pressure reached in 38 seconds. In another it was 45 pounds per square inch gauge of steam pressure reached in 43 seconds. In another, it was 50 pounds per square inch gauge of steam pressure reached in 38 seconds. In another, it was 55 pounds per square inch gauge of steam pressure reached in 43 seconds. In another, it was 60 pounds per square inch gauge of steam pressure reached in 46 seconds. In another it was 25 pounds per square inch gauge of steam pressure reached in 30 seconds.

After expanding, the product was dried by the introduction of superheated steam at about one inch of mercury absolute into the expansion chamber and continuing this operation for from five to ten minutes. That is, steam was continuously admitted while the evacuating apparatus was operated so that the pressure did not rise above about one inch of mercury absolute. It is preferred to have a moisture content of approximately 10-15% in the product before further processing.

The expanded and dried farina was then put through corrugated rolls. These corrugations cut the expanded particles up to some extent, broke up clusters, and removed some loose starch.

The vacuum expanded farina product has a volume from 1% to 2 /2 times the, original farina particles. Put conversely, the specific gravity as determined by cup weight is irom 40% to 66 the specific gravity of the original tarina particles. It is granular in appearance, the iarin'a' particles being of a snowy-white flocked with light-brown appearance, and substantially the shape of the original particles. It is capable of remarkably fast water absorption and be cooked in approximately forty-five seconds, as compared to the two to five minutes required for the original material In: cooking, /2 cup" of the processed farina is slowly stirred into 1%; cups of water containing a quarter teaspoon salt. The boiling is carried out for forty five seconds; after which the farina is ready for serving.

The coo-king operation increases the moisture content or" the farinaparticles approximately 1% for each twenty to twenty fiv'e degrees F. in.- crease in temperature; This increase is lost on vacuum expanding, andthe loss of water, plus the sudden cooling is believed tocause setting of the plasticity of the walls so: that they will not collapse upon subsequent increase" in pressure. 7

The starchy portions of the processed material are translucent. Ihe surfaccs-have-a somewhat vitre'ousappearance and the bundle of starch cells somewhat resembles a i snowball.v

In the case ofproducing a quick-cooking hominy product, regular hominy, ground to a I l-24 measurement, was'employedL Such a material, prior to pre cooking, is now available on the market.v Itsnormal cooking time is about thirty minutes:

The material; prior to treatment, had a cup weight of approximately 1'69 grams.

The material was processed in forty pound lots, without any moistening or tempering operation; Tempering may be employed, but it'has notbe'en found-to improve thematerial and; in some'oas'e's, has a deleterious effect;

Hominy is placed in the st'eaming" chamber, and evacuation carried out to approximately 0.2 inch of mercury absolute {or about 2 minutes, the hominy being-at a temperature-of at least about 40 F. to remove the non-condensible gases from the grits. Steam was then introduced to the steaming chamber accompanied by continued purging to cook the hominy and remove any condensate and non condensible gases, The product is cooked sufliciently' to gelatimz'e the starch, inactivate enzymes andsupply suihjcient plasticity for vacuum expanding. The amount of cooking required'will vary considerably with the characteristics of the grits, but may readily be determined by a preliminary test for any particular lot.

The preferred cooking or steaming cycle isto introduce steam to reach 50 pounds per square inch gauge in about 55 seconds, after which the material is expanded by opening the triggered door to the expansion chamber, which was at a pressure of about 0.2 inch of mercury absolute. Normally the pressure in the expansion chamber is not permitted to rise above about two inches of mercuryabsolute until cold setting of the vacuum expanded hominy occurs. In some instances, however, we have operated successfully with the pressure in the expansion chamber following exe plosion riding up as highas 3 /2 to 7 inches-of mere cury absoluteassmeasuredi on a-standard mere cury manometer; but-in most instances the pressure was reduced: below two-inches of mercury '16 absolute within a few minutes and before re imposition of atmospheric ressure.

In one specific example, the steaming cycle was sixty pounds per square inch gauge of steam reached in fifty-five seconds; In another, it was seventy five pounds per square inch gauge of pressure reached in seventy-seven seconds. In another, it was fifty-five pounds per square inch gauge of steampressure reached in forty-six seconds. In another, it was sixty-five pounds per square inch gauge of steam pressure reached in forty-seven s'econds. In another; it was twentyfive pounds per square inch gauge steam pressure reached in forty seconds. In another, it was thirty five pounds per square inch gauge pressure in about seconds.

After expanding, the product was dried by the introduction of superheated steam at about one inch of mercury absolute into the expansion chamber and continuing this operationfor about five minutes. That is, steam was continuously admitted while the evacuating apparatus was 0per'ate'd so that the pressure did not rise above oneinch of mercury absolute. It is preferred to have a moisture content of approximately 10-15% the product before further processing.

The expanded and dried hominy was then granlatedon corrugated rolls. These corrugations broke up clusters and removed some loose starch from-the grits.

The vacuum expanded hominy product has a Volume'from 2 /2 to 5 /2 times the originalhominy grits. Put conversely, the specific gravity as determined by cup weight is from 18.2% to 40% the specific gravity ofthe original hominy grits. It is granular in apperance having a snowy-white interior on cross-section and substantially the shape-of the original grits. It is capable of remarkably fast water absorption-and can be cooked in approximately thirty to sixty seconds as compared to thirty minutes required for the original material.

Incooking, one cup of the processed hominy is slowly stirred into two and one-quarter cups of water containing a half teaspoon salt. The boiling is carried out for thirty seconds, after which the material is ready for serving. More or less water may be added to suit individual tastes.

The cooking operation in the steaming chamber increases the moisture content of'the hominy ap-- proximately 1% for each twenty to twenty-five degrees F. increase in temperature. This increase is lost on vacuum expanding, and the loss o'fwater, plus the sudden cooling is believed to causesetting of the plasticity of the walls so that they will not collapseuponsubsequent increase in pressure.

The starchy portions of the processed material are translucent. The su-riaces-havea somewhat vitreous appearance and the bundle of starch cells somewhat resembles 'a snowball.

The foregoing detailed description is given for clearness of understanding only; and no unneces= sary limitations should be understood therefrom, as modifications will be obviousto those' skillcd in the art.

We claim:

1. The method of producing a quick-cooking cereal, which comprises: removingthe air from the cereal and substituting an atmosphere of steam under pressure; adding'steam thereto at increased pressure and temperature to raise the moisture content thereof and cook the cereal; then instantaneously reducing the pressure well below atmospheric pressure to cause an explosion resulting in expansion of the cereal; and maintaining a reduced pressure sufilcient to cold set the expanded cereal during the explosion and until cold setting of the cereal occurs, the pressure at the inception of the explosion and the extent of pressure reduction being correlated to produce an expanded quick-cooking cereal having for a period of about twenty minutes a hydration rate at least greater than that of the original cereal after immersion in water at about 200 F.

2. A cold set vacuum expanded quick-cooking cereal product produced by the process of claim 1.

3. The method of treating oats which comprises: substantially removing the air from the oats and substituting an atmosphere of steam under pressure; adding steam thereto at increased pressure and temperature to raise the moisture content thereof and cook the oats; then instantaneously reducing the pressure from at least about 25 pounds per square inch gauge to Well below atmospheric pressure to cause an explosion resulting in expansion of the oats; and maintaining a reduced pressure sufiicient to cold set the expanded oats during the explosion and until cold setting of the oats occurs, the pressure at the inception of the explosion and the extent of pressure reduction being correlated to produce an expanded product having a specific gravity between 28.5 and of the original oat grains.

4. The method as set forth in claim 3 in which the steam operation is carried on to reach a pressure of from about 25 pounds to pounds per square inch gauge.

5. The method as set forth in claim 3 in which the instantaneous pressure reduction is to 2 inches of mercury absolute or less.

6. A cold set vacuum expanded quick-cooking oat product produced by the process of claim 3.

CHARLES R. CARMAN.

JIM E. ALLISON.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,933,158 Bohn et al. Oct. 31, 1933 2,287,737 Huzenlaub June 23, 1942 2,358,251 Huzenlaub Sept. 12, 1944 2,438,939 Ozai-Durrani Apr. 6, 1948 

1. THE METHOD OF PRODUCING A QUICK-COOKING CEREAL, WHICH COMPRISES: REMOVING THE AIR FROM THE CEREAL AND SUBSTITUTING AN ATMOSPHERE OF STEAM UNDER PRESSURE; ADDING STEAM THERETO AT INCREASED PRESSURE AND TEMPERATURE TO RAISE THE MOISTURE CONTENT THEREOF AND COOK THE CEREAL; THEN INSTANTANEOUSLY REDUCING THE PRESSURE WELL BELOW ATMOSPHERIC PRESSURE TO CAUSE AN EXPLOSION RESULTING IN EXPANSION OF THE CEREAL; AND MAINTAINING A REDUCED PRESSURE SUFFICIENT TO COLD SET THE EXPANDED CEREAL DURING THE EXPLOSION AND UNTIL COLD SETTING OF THE CEREAL OCCURS, THE PRESSURE AT THE INCEPTION OF THE EXPLOSION AND THE EXTENT OF PRESSURE REDUCTION BEING CORRELATED TO PRODUCE AN EXPANDED QUICK-COOKING CEREAL HAVING FOR A PERIOD OF ABOUT TWENTY MINUTES A HYDRATION RATE AT LEAST 1/3 GREATER THAN THAT OF THE ORIGINAL CEREAL AFTER IMMERSION IN WATER AT ABOUT 200* F. 